1. Field of the Invention
The present invention generally relates to semiconductor devices, and more particularly, the present invention relates semiconductor devices having gate-all-around (GAA) structures, and to methods of fabricating the semiconductor devices having gate-all-around (GAA) structures.
2. Description of the Related Art
Semiconductor devices having GAA structures are in particular demand because of their excellent performance and due to their suppression of the short-channel effect. These advantages are incurred because a thin silicon layer that forms the channel of a GAA semiconductor device is surrounded by a gate and exclusively controlled thereby. Hence, the electric field generated at the drain has little influence on the channel region, i.e., a short-channel effect is suppressed.
A three-dimensional transistor having a GAA structure generally uses a silicon on insulator (SOI) wafer. However, the use of an SOI wafer to manufacture a semiconductor device having a GAA type transistor presents fabrication challenges, such as the high initial cost associated with producing the SOI wafer, and the creation of a floating body effect.